1. Technical Field
The disclosure relates to a fingerprint identification method and a device using the method and more particularly to a dual lens fingerprint identification method and a device using the method.
2. Related Art
As information safety is getting more important, the requirement for identity verification is increasingly higher and higher to avoid forging and modifying identity. Identity verification methods such as inputting a password, swiping card, fingerprint/vocal print/retina identification have become common methods to be against crimes.
Generally, there are two methods for reading fingerprint in fingerprint identification devices. The first method is to read a fingerprint by fixing the finger on the fingerprint identification device, and the second method is to read a fingerprint by sliding the finger relative to a detecting unit of the fingerprint identification device. The fingerprint obtained by the first method is more accurate, but a larger reading area in the fingerprint identification device is needed in the first method than in the second method. Due to the movement speed of the finger and calibrating the offsetting during the reading, a fingerprint is more difficult to be read accurately by the second method than by the first method. Therefore, fingerprint identification devices using the first method are more widely used in equipment for guaranteeing information safety.
Conventionally, an optical fingerprint identification device which reads a fingerprint by fixing the finger comprises a touch panel, a plurality of light-emitting elements, a lens and a processing unit. The touch panel is used for contacting with a finger. The light-emitting elements provide the light beams required for capturing a fingerprint image of the finger contacted with the touch panel. The processing unit determines if the fingerprint image captured by the lens is in accordance with the preset fingerprint image. The conventional optical fingerprint identification device applies the principle of total reflection, and thus certain angles are required between the lens, the finger and the light source. Furthermore, the touch panel is made of one kind of prisms. Therefore, the conventional optical fingerprint identification device has a problem of large dimensions.